Free-standing shelving has heretofore been made in which a plurality of shelves are supported in vertically spaced relation by uprights disposed between each shelf and the next lower shelf. It is common practice in such free-standing shelving, for example as shown in U.S. Pat. Nos. 3,783,801 and 3,831,533, to use spindles which have a threaded male member at one end that extends through an opening in the shelf and into a threaded socket in an axially aligned spindle at the other side of the shelf so that the end faces of the spindles can be drawn into firm contact with opposite faces of the shelf by relatively turning the spindles. With such shelving systems, it is common practice to utilize spindles in the form of turnings having a generally circular cross-section so that the rotational position of the spindle, when tightened, is immaterial. Such screw arrangements for interconnecting spindles at opposite sides of a shelf, however, are not suitable for use with spindles of non-circular cross-section which must be oriented to a predetermined angular position to the edges of the shelf.
It has also been proposed, as shown in U.S. Pat. No. 3,549,020 to form a modular shelving apparatus in which the end panels at the ends of the shelves are formed with upper extensions of reduced cross-section that extend through openings in the ends of the shelves and into the lower end of the next adjacent end panel. However, such shelving apparatus having solid end panels are not suitable for those applications where open shelving is desired.
The various objects of the present invention are to provide a free-standing shelving apparatus of the type having uprights adjacent each corner of the shelves for maintaining the shelves in spaced relation in which the uprights have a multi-sided cross-section and a non-rotatable interfit with the shelves and with the adjacent uprights to orient the same in proper angular relation with respect to the edges of the shelf; which can be assembled without the use of tools or fasteners; which is strong and rigid when assembled; and which is economical to fabricate and easy to assemble.